My research was
supported in part by Grant No. 0734783 from the National Science Foundation. Any opinions, findings, and
conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect
the views of the National Science Foundation.

Here are electronic versions of some of my articles, posters, and slide shows. You may download them and read them
for educational purposes, but please do not distribute them. Where possible, I have included a link to the journal
in which they were published.

Slope field lab: An introductory lab
for an ordinary differential equations course, based on Application 1.3 from Differential Equations and
Boundary Value Problems, Computing and Modeling, 3rd Edition by Edwards and Penney, but spiced up.

Errata for Differential Equations
and Boundary Value Problems, Computing and Modeling, 3rd Edition by Edwards and Penney. These are just the
errors and such that I've found using this book in my class.

Mathematica tools

LWProblem-v2.nb:
Mathematica notebook that generates a Stokes diagram for a WKB problem being studied by Lanier Watkins. I developed
this worksheet and the over-dense barrier worksheet at his request. He's studying Regge poles. Updated to
Mathematica 8 on May 17, 2012.

OverdenseBarrier.nb: Mathematica notebook that generates a Stokes diagram for the over-dense barrier problem in
WKB theory. (Kind of old)

Asymptotics.m: A
Mathematica package with all sorts of nice definitions for doing asymptotics and integrals and finding path
integral solutions to ODEs. (Kind of old)

The next few papers were submitted to the Mathematical Contest in Modeling, sponsored by COMAP. In this contest, teams of three students spend a weekend solving a problem in
applied mathematics. The papers they write are awarded ratings of either Outstanding, Meritorious, Honorable
Mention, or Successful Participant. There are usually 6 to 10 Outstanding papers each year.

The Duke Math Union's paper for the 1999 Math Modeling contest and its
summary. (Written by me, Sam Malone, and John Thacker, Copyright transferred to COMAP for publication in the UMAP Journal.) This one is
about determining the maximum safe occupancy of a given room and received an Outstanding rating. Note: This
document is available for educational use only. For anything else, you need permission from COMAP.

The Duke Math Union's paper for the 1998 Math Modeling contest and its
summary. (Written by me, Jeff Mermin, and John Thacker, Copyright transferred to COMAP for publication in the UMAP Journal.) This one is
about how to rank students when grades are inflated and received an Outstanding rating. Note: This document
is available for educational use only. For anything else, you need permission from COMAP.

The Duke Math Union's paper for the 1997 Math Modeling contest. I've
lost the summary. (Written by me, Robert Schneck, and Steve Wolfman.) This one is about hunting strategies for
dinosaurs and received a Meritorious rating.

The Duke Math Union's paper for the 1996 Math Modeling contest and its
summary. (Written by me, Gretta Bartels, and Fred Wang.) This one is about detecting
submarines with passsive sonar and received a Meritorious rating.

Chat Room

During the summer of 1999, I worked with Dr. Vahdat, a professor at
Duke University to develop some assignments for his networking class. We presented the chat room assignment, which
includes two fully functional security systems, at the 2001 SIGCSE Symposium. The basic chat room is designed to be
used in an introductory networking class as a "get your hands dirty with sockets" assignment. The
security systems are optional and are designed to teach how kerberos and other security systems work.

Java source code for the chat room.
Parts of this don't work very well any more because the Java cryptography extension has changed somewhat since
I wrote it, and when I last looked at it, I couldn't find a "provider" that works with recent
JDK's and with the chat room code. I don't teach this material so I haven't maintained the code.
However, you might still find this useful.

A Chat Room Assignment for Teaching
Network Security: Paper. This is a slightly fixed version of the article that appeared in the proceedings of
the symposium. As per ACM rules, it is subject to the following: Permission to make digital or hard copies of
part or all of this work for personal or classroom use is granted without fee provided that copies are not made or
distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first
page. Copyrights for components of this work owned by others than ACM must be honored. Abstracting with credit is
permitted. To copy otherwise, to republish, to post on servers or to redistribute to lists, requires prior specific
permission and/or a fee.

Other Stuff from Duke

Design Patterns by Example. This paper is
about a solution to an assignment from the object-oriented design class at Duke University (CPS108). It's
o-o-overkill, but it illustrates how even a relatively simple problem can raise some interesting design issues. I
can make the source code that goes along with it available if people want. This consists of the Bargello library
and Oodle main file. The paper, being from 1997, is just a bit outdated by now and a bit tongue-in-cheek. Consider
it still a work in progress; I know there are some mistakes in it ("procedural" vs.
"functional" programming, etc.) and I'll correct them when I have time.

An introduction to makefiles An intro to using make to maintain your compiled programs. I
wrote this to show people how to adapt the standard makefiles handed out in Duke's computer science classes for
their own uses.

Writing

A Moderately Noble Tale of Sir
Lancelot, which I wrote for a class about the Arthurian Legend, taught by Dorsey Armstrong at Duke
University. If you've ever read Chrétien de Troyes's The Knight of the Cart, you'll get many of
the references.

Several people have asked me how to view some of the files listed on this page. To read a
postscript file (one that ends in .ps) you should use some varition of ghostview. On UNIX and Linux systems, try
ghostview, gv, ggv, or kghostview. On Windows, try GSView. You can download
postcript viewers for Windows, UNIX, and other platforms from ghostscript.com and aladdin.com. Most of my
papers are also compressed with gzip. You can uncompress a file ending in .gz with gzip on many platforms, or with winzip on Windows.
Files that end in .ps.gz might have to be uncompressed before you view them, although some viewers can do the
uncompression automatically. PDF files (those that end in .pdf) can be viewed with Acrobat, available from Adobe.

Many of the icons on this site are from KDE. Other drawings were made with
The GIMP.